A double-decker elevator is known from JP 2007-331871 A. The known elevator comprises an elevator car frame in which two elevator cars are arranged vertically one above the other. The two elevator cars each stand on a carrier with guide rollers, wherein lifting cables are led around the guide rollers. In addition, provided at the elevator car frame is a drive unit around which the lifting cable is guided. Through actuation of the lifting cable by means of the drive unit the thus-suspended elevator cars can be raised and lowered relative to the elevator car frame. The two elevator cars can thereby be differently positioned within the elevator car frame.
A further double-decker elevator is described in WO 2011/073030 A1. The mechanism provided for suspension and adjustment of the elevator cars is here distinguished, by comparison with the afore-mentioned double-decker elevator, by the use of belts. Since belts are in one dimension of slender construction by comparison with a lifting cable significantly smaller bending radii around the guide rollers can be achieved. Accordingly, the diameter of a guide roller can be dimensioned to be smaller. This leads overall to a mechanism which demands less installation space at the car frame and which allows more design freedom for dimensioning of the elevator cars.
However, according to WO 2011/073030 A1 the belt guide at the elevator car frame for realization of the suspension of the elevator cars is relatively complicated. The numerous deflections of the belt at the elevator car frame lead to, in particular, a mechanism comprising numerous guide rollers. In addition, the elevator cars have to be equipped with under tensioning means in order to prevent jumping of the elevator car in the elevator car frame in the event of strong decelerations such as, for example, in the case of travel onto a buffer or safety braking.